Various release devices are utilized in archery to assist the archer in pulling a bowstring to a fully drawn position and then releasing the bowstring to fire the arrow. Many of these devices include mechanical grippers which engage the bowstring directly, or which engage nock elements mounted on the bowstring. Other devices use rope looped about the bowstring as the release mechanism. Examples of such release devices may be found in my earlier U.S. Pat. Nos. 5,680,851 and 5,685,286, both of which are incorporated herein by reference. Additional examples are disclosed in my U.S. Pat. No. 5,803,068, also incorporated herein by reference.
There is a continuing demand, however, for even more sensitive and accurate release devices, particularly for competition archery where every advantage is sought by the archer.
This invention relates to improved release devices which utilize essentially non-moving, pressure sensitive triggers, and which also eliminate torque on the bowstring as well as on the jaws of the release device. Other features and advantages will be discussed further herein.
In one exemplary embodiment, the release includes a handle body which supports gripping jaws within a jaw release housing (which may be similar to that disclosed in the above identified '286 patent), a combined cocking/hammer bar, a trigger and a connector for attachment to a wrist strap or the like. The cocking/hammer bar is pivotally mounted within the handle body, with a hammer head at one end in alignment with a jaw release firing pin, and a cocking trigger at the opposite end, extending outside and to the rear of the handle body.
The firing trigger mechanism is also pivotally mounted within the body, with a firing trigger also extending outside but forward of the handle body (for engagement with the index finger), and an opposite actuator end generally adjacent the hammer head of the combined cocking/hammer bar. Interposed between the trigger actuator end and the hammer head is a roller sear, rotatably mounted within a generally Z-shaped housing or crank, also pivotally secured within the handle body.
In an uncocked position, the cocking/hammer bar is spring biased to a release or firing position, with the head having pushed the firing pin to its forwardmost release position. At the same time, the Z-shaped crank is biased in a cocking direction, but out of engagement with the hammer head. The trigger mechanism in this uncocked position is biased toward a non-firing mode, recognizing, however, that there is essentially no perceptible trigger movement when firing.
To cock the release, the cocking trigger is pulled rearwardly against its normal spring bias, such that the hammer head rides over the roller sear as the Z-shaped crank is forced simultaneously to rotate away from the hammer head. Once over the roller sear, the hammer head moves into a recess in the sear housing or crank as the latter rotates in an opposite direction under its own normal spring bias, the roller capturing the hammer head in the cocked position. With extended leverage built into the firing trigger mechanism, only slight pressure need be exerted on the firing trigger to cause the opposite end of the trigger mechanism (which is in engagement with one end of the crank) to pivot the crank just sufficient to permit the hammer head to again ride over the roller sear, escaping the roller sear housing and driving the firing pin forward under the influence of the cocking/hammer bar springs.
It should be noted that in the cocked position, a very slight clearance is maintained between the firing pin and the hammer head, so that there is no load on the firing pin at any time prior to firing.
The release as described also incorporates a trigger sensitivity adjustment between the actuator end of the firing trigger and the sear housing, and a trigger "travel" adjustment between the handle body and the firing trigger mechanism. A noise suppression spring is also provided between the handle body and the cocking/hammer bar at a location adjacent the hammer head.
Another feature of the invention relates to the use of a bronze bushing through which the firing pin slides. This bushing prevents firing pin wear on the softer aluminum handle body.
The remote end of the release handle body supports a disk-like link pin, rotatable about its own axis, and which supports a screw connector extending rearwardly of the handle for attachment to a wrist strap connector. The wrist strap and connector assembly is the subject of a separate co-pending application concurrently filed with this application and entitled "Wrist Strap Connector For A Bowstring Release",
In another embodiment of the invention, the otherwise solid aluminum handle body has a rearwardly opening slot in which the cocking/hammer bar, trigger mechanism, firing pin and sear housing are located. In this arrangement, the firing trigger extends rearwardly of the handle body for engagement by the user's thumb. The cocking trigger of the cocking/hammer bar also extends rearwardly out of the slot in the handle body, but sufficiently remote from the firing trigger to avoid interference. This second embodiment also omits the wrist strap connector as described above. The jaws and jaw release housing in this second embodiment may be disclosed in my above-identified co-pending '038 application.
In both of the exemplary embodiments, the fundamental relationship between the firing trigger, cocking/hammer bar, firing pin, Z-shaped sear housing and sear roller is essentially identical, even though certain components have different shapes while others are identical. In both embodiments, the jaw housing is rotatable relative to the handle body and, in the first described embodiment, the handle body is also rotatable (about two mutually perpendicular axes) relative to the wrist strap thereby reducing if not completely eliminating torque on the bowstring and/or release jaws. Moreover, the "non-moving" trigger mechanism and load free firing pin provide for even greater sensitivity and accuracy.
In its broader aspects, therefore, the present invention relates to a bowstring release comprising a handle body, said handle body supporting a jaw release housing and associated jaws actuable by means of a firing pin extending into an interior portion of the handle body; a hammer bar including a hammer head engagable with the firing pin and movable to a cocked position by means of a cocking trigger portion of the hammer bar, the cocking trigger extending outside the handle body; a firing trigger assembly including a firing trigger outside the handle body and a trigger actuating arm located within the handle body; and a roller sear housing and roller sear assembly, the housing having one end engageable with the trigger actuating arm, and the roller engageable with the hammer head; wherein the hammer head is seated in the roller sear housing in a cocked position, and wherein pressure applied to the firing trigger causes the roller sear housing to release the hammer head for firing engagement with the firing pin.
In another aspect, the invention relates to a bowstring release comprising a handle body, said handle body supporting a jaw release housing and associated jaws actuable by means of a firing pin extending into an interior portion of the handle body; a hammer bar including a hammer head engagable with said firing pin and movable to a cocked position by means of a cocking trigger portion of said hammer bar, said cocking trigger extending outside said handle body; a firing trigger assembly including a firing trigger outside said handle body and a trigger actuating arm located within said handle body; and a roller sear housing and roller sear assembly, said housing having one end engageable with said trigger actuating arm, and said roller engageable with said hammer head; wherein said hammer head is seated in said roller sear housing in a cocked position, and wherein pressure applied to said firing trigger causes said roller sear housing to release said hammer head for firing engagement with said firing pin.
Other objects and advantages will become apparent from the detailed description which follows.